Wb. Holzapfel et al., New constraints on Gruneisen parameters applications to equations of statefor pressure markers, HIGH PR RES, 19(1-6), 2000, pp. 731-735
"Regular" linear relations between shock and particle velocities, u(s) = u(
so) + c . u(p), imply a divergence of the Hugoniot pressure pH at a critica
l compression V-c/V-o = (c - 1)/c, where the thermal pressure Deltap(th)=(g
amma /V).DeltaU(th)=p(H)-p(T) becomes very large with respect to the cold (
isothermal) pressure p(T) at this compression. The Hugoniot relation for th
e total internal energy U-H results in this case in the relation gamma (c)
= 2(c - 1) for the Gruneisen parameter in this region. Experimental data fo
r the zero pressure value gamma (o) and its derivative Gamma (gammao) toget
her with theoretical data for the limiting value gamma (infinity) = 2/3, an
d the additional experimental value gamma (c) are then used to determine th
e thermal (phonon) pressure with the common Mie-Gruneisen assumption.